Bright Tin CULMO 20 Brigt Tin CULMO 20 is based upon sulphuric acid, free from formalin and deposits bright tin layers. These layers are resistant to fingerprints and show good solderability, even after an accelerated aging test e.g. 16 h at 155 C. Bright Tin CULMO 20 is weakly foaming and especially suitable for barrel plating. It may also be used in continuous plating lines, if a good electrolyte exchange and large anode surface can be assured. Electrolyte exchange and metal content determine the applicable cathodic current density. Bright Tin CULMO 20 is extraordinary stable and easy to handle. The information in this data sheet is based on laboratory as well as practical experience. Figures quoted for operating limits and replenishment quantities are for guidance only. Actual values necessary will depend on the components being plated (material and geometry), their application and plating plant conditions. Important: Please read this instruction carefully prior to the use of the process and carefully follow all the parameters that have a direct influence on the operation. We reserve the right to make technical changes. In the interest of safety, please pay attention to the hazard warnings on the labels of the containers. The minimum shelf life of the products is included on the labels and is also available in the appropriate Quality Assurance (QA03). The current IMDS number of the layer deposited from the process is available on the internet at www.schloetter.com/downloads. For the storage of chemical products the TRGS 510 must be followed. If the additives used in this process contain a SVHCsubstance, then this will be specified in the corresponding Material Safety Data Sheet, section 15. BATH 10012E Page 1 of 6 Issue 03.06.2015
1.0 TECHNICAL INFORMATION AND EQUIPMENT REQUIREMENTS Tanks: rubber lined steel, polypropylen or PVC Agitation: barrel: approx. 4 rpm continuous plating line: best possible Filtration: continuous, 6 8 turnovers/h Cooling: plastic coated steel pipes or thin walled plastic pipes Anodes: pure tin; min. 99.95 % material number 2.3500 Anode bags: polypropylene fabric Anode hooks: plastic lined, especially for tin electrolytes 2.0 MAKEUP AND OPERATING CONDITIONS 2.1 Product names List of products required Product name Article no. (AN) SG Sulphuric acid, conc. (96 %) chem. pure supplied by user* 1.84 Tin Salt SU 100000 1.34 Starter CULMO 21 100017 1.55 Brightener CULMO 22 100018 0.99 * The current product qualities respectively specifications recommended by us can be found on the internet at www.schloetter.com/downloads. 2.2 Requirements for a 100 litre bath 2.2.1 When used as barrel application Product name AN SG Quantity Sulphuric acid, conc. (96 %) chem. pure 120100 1.84 10 ltr. Tin Salt SU 100031 3 kg Starter CULMO 21 100051 0,96 2 ltr. Brightener CULMO 22 100052 0,89 0.3 ltr. 2.2.1 When used in continuous plating lines Product name AN SG Quantity Sulphuric acid, conc. (96 %) chem. pure 120100 1.84 6.8 ltr. Tin Salt SU 100031 4 kg Starter CULMO 21 100051 0,96 2 ltr. Brightener CULMO 22 100052 0,89 0.3 ltr. BATH 10012E Page 2 of 6 Issue 03.06.2015
2.3 Make up sequence for a 100 litre bath All tanks and associated equipment must be thoroughly cleaned prior to use. fill 70 litres of deionised water into tank slowly add with constant stirring the required quantity of sulphuric acid, in compliance with the valid safety measures add the required quantity of Tin Salt SU let the electrolyte cool to operating temperature add 2 litres of Starter CULMO 21 mix well add 0.3 litres of Starter CULMO 22 mix well make up with deionised water to final volume mix thoroughly The electrolyte is ready for use when the operating temperature has been reached. NB When makingup the electrolyte, it has to be taken into consideration, that the temperature of the solution raises quickly by the exothermic reaction which forms by the addition of sulphuric acid, conc.. If the sulphuric acid is added too quickly, an intensive heat can develop which causes spattering of the corrosive liquid. It s absolutely necessary to observe the safety measures applicable to makeup and handling of this copper electrolyte (protective clothing, goggles, rubber gloves). 2.4 Concentrations and operating conditions 2.4.1 When used as barrel application Range Optimum Tin(II) 10 20 15 g/l Sulphuric acid 120 65 200 110 180 100 g/l ml/l Starter CULMO 21 15 25 20 gl/l Brightener CULMO 22 2 5 3 ml/l Temperature range 10 25 C Cathodic current density 0.6 A/dm² Anodic current density 2.5 A/dm² Deposition rate at 2 A/dm² 1 µm/min. BATH 10012E Page 3 of 6 Issue 03.06.2015
2.4.2 When used in continuous plating lines Range Optimum Tin(II) 15 30 20 g/l Sulphuric acid 100 55 150 80 125 70 g/l ml/l Starter CULMO 21 15 20 20 gl/l Brightener CULMO 22 2 5 3 ml/l Temperature range 10 25 C Cathodic current density 15 A/dm² Anodic current density 2.5 A/dm² Deposition rate at 2 A/dm² 1 µm/min. 2.4 Consumption and replenishment Consumption is mainly due to dragout and therefore very much dependent on the geometry and condition of the parts as well as on the plant operation. Approximate values for replenishment: Additive Starter CULMO 21 (by dragout) Brightener CULMO 22 Replenishment / Consumption 1 2 ml/m² approx. 5 l/10 kah 3.0 PROCESS SEQUENCE Our technical field service and service department would be pleased to provide you with suitable process sequences and methods. 4.0 MAINTENANCE AND FUNCTION OF THE BATH COMPONENTS 4.1 Tin The tin content ranges in dependence on the application between 10 25 g/l, with an optimum of 15 g/l for barrel and 20 g/l for continuous plating lines. Lack of tin is replenished with Tin Salt SU (50 % of tin). We would be pleased to provide you with suitable analysis methods. BATH 10012E Page 4 of 6 Issue 03.06.2015
4.2 Sulpuric acid The sulphuric acid concentration depends on the field of application and from the tin content. For barrel parts a content of 180 g/l is recommended. For continuous plating, optimum 125 g/l. Lack of sulphuric acid may only be replenished with sulphuric acid chemically pure. A too low content of sulphuric acid reduces the conductivity of the tin electrolyte on the other hand a too high content leads to disturbances by anode passivation. 4.3 Starter CULMO 21 Starter CULMO 21 is only indirectly interested in the brightening effect. The concentration should be 15 25 ml/l, optimum approx. 20 ml/l. The consumption depends on the local dragout losses. Normally approx. 1 2 ml/l of Starter CULMO 21 are required per m² surface throughput. 4.4 Brightener CULMO 22 Consumption of Brightener CULMO 22 is due to electrolyte load. Approx. 5 litres of Brightener CULMO 22 are required for a throughput of 10 kah. Lack of Brightener CULMO 22 is indicated by the reduction of brightness especially in the low current density area. Brightener CULMO 22 is added in increments of 1 2 ml/l in case of an insufficient brightness of the deposited tin layers. Excess of Brightener CULMO 22 causes dark stains and especially in areas with a strong electrolyte flow a step deposition. In an extreme case the tin deposition is in some areas totally inhibited. The excess can be compensated by adding Starter CULMO 21 in increments of 5 ml/l. 4.5 Operating temperature Bright Tin CULMO 20 can be operated in a temperature range of 10 25 C. At higher electrolyte temperatures the brightness of the tin coatings decreases in the low current density area. This can be compensated by the addition of Brightener CULMO 22. For tin plating of small components (chips or similar) with a big total surface with big surface low temperatures are necessary. The electrolyte must be cooled. 4.6 Foam formation Bright Tin CULMO 20 contains only weakly foaming additives so that generally no disturbing foam formation occurs. In specific applications it s required to prevent the foam formation completely. Antifoam SN in the concentration of 0.1 0.5 ml/l can be added. BATH 10012E Page 5 of 6 Issue 03.06.2015
5.0 TROUBLE SHOOTING 5.1 Fault finding chart No information available at present. 6.0 EFFLUENT Legal regulations must be observed for disposal of the Bright Tin CULMO 20. Different regulations normally apply for the additives and the readymade electrolyte. Please refer to section 13 of the appropriate Material Safety Data Sheet for disposal code and recommendations. The following detoxification sequence is only considered to be an aid: Bright Tin CULMO 20 does not contain complexing agents. Heavy metals can therefore precipitated by a simply neutralisation at a ph value of 7 8. 7.0 SAFETY Reasonable care is required when handling chemical products. Only personnel specially trained on working with chemicals should be deployed with their handling. EC Material Safety Data Sheets must be made available to all personnel dealing with the chemicals to ensure they have all required information about product composition, hazards identification, firstaid measures, handling and storage, exposure controls, toxicological and ecological information, etc. It is required to ensure the supply and use of suitable protective clothing and equipment. The user must verify the designated purpose of the electrolyte. Previous experience has shown that not all metal surfaces are suitable for a troublefree electroplating. The above mentioned data are made according to our best knowledge. Consistent operation of the working solution requires appropriate maintenance Bright Tin CULMO 20 is a process of GmbH & Co KG. It can only be operated with the products described in this technical data sheet. Use of other chemicals (also partly) will impair quality and invalidates our service and quality commitments (quality assurance). BATH 10012E Page 6 of 6 Issue 03.06.2015